Fastening element for a smartphone holder



FIG. 1 is a top view of the smartphone holder showing the new design;

FIG. 2 is a view of the smartphone holder in perspective at an angle from the top and side;

FIG. 3 is a view of the smartphone holder in perspective at a different angle from the top and side; and,

FIG. 4 is a view of the smartphone holder in perspective at an angle from the bottom and the side. 

CLAIM The ornamental design for a fastening element for a smartphone holder, as shown. 